Porsche introduced this generation of the 911 model series as a new model, even though it looks almost identical to the older one. The new models consist of Coupe, Cabriolet and Targa body styles. There was an initial choice of two all-new flat-6 powerplants, but later in 2010, the Turbo, GT3 and GT3 RS variants debuted, with the GT2 RS coming after that. A new Carrera GTS model debuted in 2011 with yet another engine tune, followed by an expensive Speedster limited-edition with the same engine, while a Carrera 4 GTS came later. The rear-wheel-drive Carrera 2 and Targa 4, and the all-wheel-drive Carrera 4, all get the 3.6-litre engine. The Carrera 2S, the Targa 4S and the Carrera 4S get the 3.8-litre engine. The new-for-2011 Carrera GTS Coupe and Cabriolet as well as the Speedster convertible get a mildly-tuned version of the 3.8-litre. The GT3 and GT3 RS get a further upgraded version of the 3.8-litre engine. And the Turbo and Turbo S get a turbocharged 3.8-litre in different states of tune, with all-wheel-drive. The GT2 RS gets a 3.6-litre turbo engine with even more power and rear-wheel-drive. For the first time among Porsche models, direct fuel injection has been introduced, as has a new optional 7-speed double-clutch automanual gearbox known as the Porsche-Doppelkupplung (PDK), available alongside the standard 6-speed manual on all but the GT3 and GT2 models. The PDK gearbox offers better acceleration and fuel economy than the manual version. There is the choice to combine PDK with Porsche's optional Sport Chrono Plus gearbox mapping, including Launch Control. Additional new features include front and rear LED driving lights, bi-xenon headlights, dynamic cornering lights, and a mild overall facelift. Interior features include a CD stereo, leather upholstery, optional multimedia system, common power accessories and more, though almost all other convenience features are optional. Safety includes multiple airbags, stability control and pop-up roll hoops for the convertible.